diff options
| author | Shengming Hu <hu.shengming@zte.com.cn> | 2026-02-13 14:29:32 +0800 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2026-02-13 09:33:14 -0500 |
| commit | 53b2fae90ff01fede6520ca744ed5e8e366497ba (patch) | |
| tree | 6762965ca4f299aab105279f98160743f3e967ea | |
| parent | fa4820b893843f7ad5e1b5c446a92426c5c946ce (diff) | |
function_graph: Restore direct mode when callbacks drop to one
When registering a second fgraph callback, direct path is disabled and
array loop is used instead. When ftrace_graph_active falls back to one,
we try to re-enable direct mode via ftrace_graph_enable_direct(true, ...).
But ftrace_graph_enable_direct() incorrectly disables the static key
rather than enabling it. This leaves fgraph_do_direct permanently off
after first multi-callback transition, so direct fast mode is never
restored.
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260213142932519cuWSpEXeS4-UnCvNXnK2P@zte.com.cn
Fixes: cc60ee813b503 ("function_graph: Use static_call and branch to optimize entry function")
Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/fgraph.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index cc48d16be43e..4df766c690f9 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -1303,7 +1303,7 @@ static void ftrace_graph_enable_direct(bool enable_branch, struct fgraph_ops *go static_call_update(fgraph_func, func); static_call_update(fgraph_retfunc, retfunc); if (enable_branch) - static_branch_disable(&fgraph_do_direct); + static_branch_enable(&fgraph_do_direct); } static void ftrace_graph_disable_direct(bool disable_branch) |